A Decision Framework for Vehicle Inspection and Maintenance Programs Using Health Benefit Analysis

Motor vehicle inspection and maintenance (I/M) programs have been considered cost-effective for the control of air pollution particularly in heavily polluted urban areas where vehicles are responsible for a substantial fraction of total emissions. The primary benefits of I/M programs are generally measured by the public health improvements attributable to reductions in air pollution. On the other hand, past practices in the U.S. and elsewhere have demonstrated that the design and implementation of I/M programs often involves many challenges, and the actual effects of this policy tool can be highly uncertain. However, this uncertainty issue has traditionally been ignored in the cost-benefit analysis of I/M programs. In this study, we develop a decision framework that links the participation levels of I/M programs to the associated health benefits to help policymakers understand the desired level of participation that makes the programs cost-effective. This framework also forms the basis of an improved cost-benefit analysis of I/M programs that takes into account the key uncertainty about the actual effects of the programs. Using this framework, a case study is conducted in Bangkok, Thailand to evaluate the health benefits of an upgraded I/M system being proposed that targets the rapidly growing vehicle emissions in the city.